Field of the Invention
The present invention relates to a processing-liquid supply apparatus and a processing-liquid supply method for supplying processing liquid to a surface of a target substrate such as a semiconductor wafer or an LCD glass substrate.
Description of Background Art
Generally, in photolithographic technology for manufacturing semiconductor devices, photoresist is coated on substrates such as semiconductor wafers and FPD substrates (hereinafter referred to as wafers), a resulting resist film is exposed to light through a predetermined circuit pattern, and developing treatment is conducted on the exposed pattern. Accordingly, a circuit pattern is formed on the resist film.
Conventionally, there is a circulatory filtration system for chemical-liquid supply structured to have the following (see JP 2011-238666A): a first vessel and a second vessel to store a chemical liquid (processing liquid); a first pump provided for a first pipeline connecting the first vessel and the second vessel so as to flow the chemical liquid stored in the first vessel to the second vessel; a first filter set in the first pipeline;
a second pipeline connecting the first vessel and the second vessel; and a second pump provided for the second pipeline to flow the chemical liquid stored in the second vessel to the first vessel.
Also, as a liquid processing apparatus of a circulatory filtration system using one filter device, there is a photoresist coating-liquid supply apparatus to have the following (see WO2006/057345A1): a buffer vessel for a resist coating liquid (processing liquid); a circulatory filtration device that pumps out part of the photoresist coating liquid from the buffer vessel, filters the liquid through a filter and returns the liquid to the buffer vessel; and a pipeline to flow the photoresist coating liquid from a buffer vessel or a circulation device to the photoresist coating device. JP 2001-77015A describes a structure where a pump is positioned on each of the upstream side and downstream side of a filter. The entire contents of these publications are incorporated herein by reference.